The present invention relates generally to the field of elastic used in garments and in particular to a new and useful elastomeric composite tape that can be used in garments, suitable for body oil and skin contact application.
The elastic tape most commonly used in garments today is primarily manufactured from natural rubber obtained from the tropical tree xe2x80x9cHeavea Brasiliensisxe2x80x9d. Natural rubber, when suitably compounded, has a variety applications ranging from the tire industry to floor mats. Natural rubber is an elastomer that is well suited for use in the clothing industry because natural rubber elastic tape provides a garment with lower modulus of elasticity, high tear strength, and low permanent set. It is very strong but can be made soft.
But, unfortunately, natural rubber is nonpolar and swells in all nonpolar hydrocarbon solvents/oils, losing its strength and effectiveness. Thus, natural rubber tapes are not an ideal component for uses and end products that are likely to result in the rubber coming into contact with oils like body oil and sun tan oil.
Several patents describe blends of rubbers provided for a variety of different purposes.
U.S. Pat. No. 5,118,546, for example, teaches a sulfur-curable elastomeric composition for a tire tread having 60-95% wt. rubber selected from a group that includes natural rubber, nitrile rubber, and mixtures thereof. The remaining portion is derived from a blend of 25-75% wt. polychloroprene and 25 to 75% wt. epoxidized natural rubber.
The polychloroprene and epoxidized natural rubber are first masticated under conventional temperature and then later combined with a rubber stock comprising the elastomeric composition which may include natural and/or nitrile rubber. The rubber stock is also combined with various additives such as reinforcing agents, fillers, accelerators, vulcanizing agents, processing oils and antioxidahts.
U.S. Pat. No. 5,118,546 does not teach the application and advantages of an elastomer blend to clothing and elastic garments in particular. The patent teaches high proportions of natural rubber, nitrile rubber, polychloroprene, and epoxidized natural rubber.
A rubber composition containing a blend of natural rubber and epoxidized natural rubber for application to skin in the form of a tape is taught by U.S. Pat. No. 5,447,976. The blend is masticated in a Banbury mixer and combined with various ingredients such as antioxidants, accelerators, reinforcement fibers, fillers, pigments, dyes, and processing oils. Processing oils are required to make the composition. The rubber composition is disclosed for use as a tape in legbands, straps and swimwear garment edges, as well as in other clothing, but the patent discourages the use of polychloroprene in rubber compounds used in garments.
U.S. Pat. No. 5,736,593 discloses a ternary blend of polyisoprene (e.g., natural rubber), epoxidized natural rubber, and chlorosulfonated polyethylene. In particular, a composition is disclosed having about 76-94% wt. of poyisoprene, 3-12% wt. of epoxidized natural rubber, and 3-12% wt. chlorosulfonated polyethylene. The rubber composition is preferably used for tire treads.
U.S. Pat. No. 5,352,739 discloses a compatibilized rubber composition and a process for compatibilizing polar and nonpolar rubber blends, using compatibilzing agents such as ethylene vinyl acetate copolymer, ethylene methacrylate copolymer, and ethylene/propylene/diene terpolymer (EPDM) or ethylene/propylene (EP) rubber grafted with a polar monomer such as methyl methacrylate. In particular, the patent discloses a polar rubber such as nitrile or polychloroprene (also known as neoprene) blended with a nonpolar elastomer such as EPDM or EP in the presence of a copolymer compatibilizer.
U.S. Pat. No. 5,397,833 teaches a compatibilized rubber composition blending an ethylene/acrylate/acrylic acid terpolymer with two or more different polar and nonpolar rubbers selected from polychloroprene, natural rubber, and nitrile rubber among others. Preferred compositions are limited to only natural and nitrile rubbers, and the compositions disclosed do not contain epoxidized natural rubber.
The availability of other rubber blend compositions more suitable for use in body contacting applications is desirable.
It is, therefore, an object of the invention to provide an elastomeric composite for use in garments that has superior qualities of each individual component elastomer or rubber used alone, while retaining many of the preferred qualities of each component.
It is a further object of the invention that the elastomeric composition have high chlorine, salt water, and oil resistance to body oil and tanning oils, a low permanent set, a low modulus of elasticity, and high strength, while remaining cost efficient to produce.
Accordingly, an elastomeric composite is provided having a compatible blend of natural rubber (NR), polychloroprene (CR), nitrile rubber (NBR) and epoxidized natural rubber (ENR). The invention provides a compatible blend of the four different natural and synthetic rubber polymers to achieve oil resistance particularly suited for use with clothing that is designed for contact with skin. The elastomeric composite of the invention has about 20 to 65% by weight natural rubber (NR), about 5 to 30% by weight nitrile rubber (NBR), about 10 to 25% by weight epoxidized natural rubber (ENR), and about 1 to 5% by weight polycholoroprene (CR).
An elastic tape of the invention made from the elastomeric composite is suitable for use in garments because it does not swell in the presence of body oils and other oils that are applied to skin.
When formed as a tape, the elastomeric composite is extremely useful for leg bands, straps, and lining the contours of leg and head openings in swim suits and other garments. The elastic tape is also suitable for use in face masks, head bands, and shower caps.
The foregoing and other objects and advantages will become apparent to those skilled in the art upon reading the following detailed description of the preferred embodiments.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying tables and descriptive matter in which a preferred embodiment of the invention is illustrated.